Add docstrings (#9)

* Add docstrings

* Concise

* Update arg name

src/babashka/json.clj

@@ -36,21 +36,31 @@
   (def ^:private read-fn read-fn))
 
 (defn read
+  "Returns a Clojure value from the JSON reader.
+  
+  Options:
+    :key-fn - Convert JSON keys using this function. Defaults to keyword."
   ([reader] (read reader nil))
   ([reader opts]
    (read-fn reader opts)))
 
 (defn read-str
+  "Returns a Clojure value from the JSON string.
+
+  Options:
+    :key-fn - Convert JSON keys using this function. Defaults to keyword."
   ([s] (read-str s nil))
   ([s opts]
    (read-str-fn s opts)))
 
 (defn write-str
-  ([s] (write-str s nil))
-  ([s opts]
-   (write-str-fn s opts)))
+  "Returns a JSON string from the Clojure value."
+  ([x] (write-str x nil))
+  ([x opts]
+   (write-str-fn x opts)))
 
 (defn ->json-reader
+  "Returns a JSON reader."
   ([x] (->json-reader x nil))
   ([x opts]
    (internal->json-reader x opts)))